from rest_framework import serializers

from core.serializers.base import BaseModelSerializer
from apps.time_entries.models import TimeEntry
from apps.projects.models import Project
from apps.tags.models import Tag


class TimeEntrySerializer(BaseModelSerializer):
    """
    Output serializer for TimeEntry.
    """
    start_time = serializers.DateTimeField(format="%Y-%m-%d %H:%M:%S")
    end_time = serializers.DateTimeField(format="%Y-%m-%d %H:%M:%S", allow_null=True)

    class Meta:
        model = TimeEntry
        fields = BaseModelSerializer.Meta.fields + (
            "workspace",
            "user",
            "project",
            "description",
            "start_time",
            "end_time",
            "duration",
            "tags",
            "is_billable",
            "hourly_rate",
            "currency",
        )
        read_only_fields = fields


class TimeEntryCreateSerializer(serializers.Serializer):
    """
    Validates input data for creating/starting a time entry.
    """
    workspace_id = serializers.UUIDField()
    project_id = serializers.PrimaryKeyRelatedField(
        queryset=Project.objects.filter(is_deleted=False), 
        required=False, 
        allow_null=True, 
        source='project'
    )
    start_time = serializers.DateTimeField()
    end_time = serializers.DateTimeField(required=False, allow_null=True)
    description = serializers.CharField(required=False, allow_blank=True, default="")
    tags = serializers.PrimaryKeyRelatedField(
        queryset=Tag.objects.filter(is_deleted=False), 
        many=True, 
        required=False
    )
    is_billable = serializers.BooleanField(default=False)


class TimeEntryUpdateSerializer(serializers.Serializer):
    """
    Validates input data for updating an existing time entry.
    """
    project_id = serializers.PrimaryKeyRelatedField(
        queryset=Project.objects.filter(is_deleted=False), 
        required=False, 
        allow_null=True, 
        source='project'
    )
    start_time = serializers.DateTimeField(required=False)
    end_time = serializers.DateTimeField(required=False, allow_null=True)
    description = serializers.CharField(required=False, allow_blank=True)
    tags = serializers.PrimaryKeyRelatedField(
        queryset=Tag.objects.filter(is_deleted=False), 
        many=True, 
        required=False
    )
    is_billable = serializers.BooleanField(required=False)


class TimeEntryStopSerializer(serializers.Serializer):
    """
    Optional specific serializer for stopping a timer manually.
    """
    end_time = serializers.DateTimeField(required=False, allow_null=True)